A.I. Explanation:

Option 1: "Good habits are developed in them."

Explanation: While the text mentions that sports helps inculcate good habits, it does not directly connect this to the development of discipline through playing games. The focus is more on the specific aspect of following rules and regulations, which is essential for discipline.

Option 2: "They want to choose sports as career."

Explanation: This option suggests a motivation to pursue sports as a career, which is mentioned in the text. However, it does not address how playing games specifically contributes to discipline. The text emphasizes discipline through adherence to rules rather than career aspirations.

Option 3: "They get a habit to follow rules and regulations."

Explanation: The text clearly states that students learn to live in discipline by following the rules and regulations of games. This directly correlates to how playing games instills discipline, as it requires adherence to established guidelines, fostering a sense of responsibility and order.

Option 4: "Mental ability gets improved by playing."

Explanation: Although the text mentions that playing sports improves mental ability, this does not relate to the concept of discipline. The focus of the question is on how discipline is developed through sports, which is not addressed by this option.